Display apparatus and method of driving display panel using the same

Abstract

A display apparatus includes a display panel, a first gate driver, a second gate driver, a third gate driver, and a data driver. The display apparatus is operable in a low frequency driving mode, and the low frequency driving mode includes a writing frame and a holding frame. At least one of gate power voltages used to generate a first gate signal, a second gate signal, and an emission signal has a first voltage level in the writing frame of the low frequency driving mode and a second voltage level in the holding frame of the low frequency driving mode. The data voltage is applied to the pixel in the writing frame of the low frequency driving mode. The data voltage applied to the pixel in the writing frame of the low frequency driving mode is maintained in the holding frame of the low frequency driving mode.

What is claimed is: 
     
       1. A display apparatus comprising:
 a display panel comprising a pixel including a first switching element of a first type and a second switching element of a second type that is different from the first type; 
 a first gate driver configured to output a first gate signal to the first switching element of the first type; 
 a second gate driver configured to output a second gate signal to the second switching element of the second type; 
 a third gate driver configured to output an emission signal to the pixel; and 
 a data driver configured to output a data voltage to the pixel, 
 wherein the display apparatus is operable in a low frequency driving mode, and the low frequency driving mode includes a writing frame and a holding frame, 
 wherein at least one of gate power voltages used to generate the first gate signal, the second gate signal, and the emission signal has a first voltage level in the writing frame in the low frequency driving mode and a second voltage level that is different from the first voltage level in the holding frame of the low frequency driving mode, both of the first voltage level and the second voltage level corresponding to a same gate state selected from a gate-high state and a gate-off state, 
 wherein the data voltage is applied to the pixel in the writing frame of the low frequency driving mode, and 
 wherein the data voltage applied to the pixel in the writing frame of the low frequency driving mode is maintained in the holding frame of the low frequency driving mode. 
 
     
     
       2. The display apparatus of  claim 1 , wherein the first switching element of the first type is a polysilicon thin film transistor, and
 wherein the second switching element of the second type is an oxide thin film transistor. 
 
     
     
       3. The display apparatus of  claim 1 , wherein the first switching element of the first type is a p-type transistor, and
 wherein the second switching element of the second type is an n-type transistor. 
 
     
     
       4. The display apparatus of  claim 1 , wherein the pixel comprises:
 a light emitting element comprising an anode electrode and a cathode electrode to which a low power voltage is applied; 
 a first pixel switching element comprising a first control electrode connected to a first node, a first input electrode connected to a second node, and a first output electrode connected to a third node; 
 a second pixel switching element comprising a second control electrode to which the first gate signal is applied, a second input electrode to which the data voltage is applied, and a second output electrode connected to the second node; 
 a third pixel switching element comprising a third control electrode to which the second gate signal is applied, a third input electrode connected to the first node, and a third output electrode connected to the third node; 
 a fourth pixel switching element comprising a fourth control electrode to which a data initialization gate signal is applied, a fourth input electrode to which an initialization voltage is applied, and a fourth output electrode connected to the first node; 
 a fifth pixel switching element comprising a fifth control electrode to which the emission signal is applied, a fifth input electrode to which a high power voltage is applied, and a fifth output electrode connected to the second node; 
 a sixth pixel switching element comprising a sixth control electrode to which the emission signal is applied, a sixth input electrode connected to the third node, and a sixth output electrode connected to the anode electrode of the organic light emitting element; 
 a seventh pixel switching element comprising a seventh control electrode to which an organic light emitting element initialization gate signal is applied, a seventh input electrode to which the initialization voltage is applied, and a seventh output electrode connected to the anode electrode of the organic light emitting element; and 
 a storage capacitor comprising a first electrode to which the high power voltage is applied and a second electrode connected to the first node. 
 
     
     
       5. The display apparatus of  claim 4 , wherein the first pixel switching element, the second pixel switching element, the fifth pixel switching element, and the sixth pixel switching element are polysilicon thin film transistors, and
 wherein the third pixel switching element, the fourth pixel switching element, and the seventh pixel switching element are oxide thin film transistors. 
 
     
     
       6. The display apparatus of  claim 1 , wherein the second gate signal has a first frequency in the low frequency driving mode, and
 wherein the first gate signal and the emission signal have a second frequency that is greater than the first frequency in the low frequency driving mode. 
 
     
     
       7. The display apparatus of  claim 6 , wherein the second gate signal is generated based on a first gate high voltage level and a first gate low voltage level in the writing frame of the low frequency driving mode, and
 wherein the second gate signal is generated based on a second gate high voltage level that is lower than the first gate high voltage level and a second gate low voltage level that is greater than the first gate low voltage level in the holding frame of the low frequency driving mode. 
 
     
     
       8. The display apparatus of  claim 7 , wherein the first gate signal and the emission signal are generated based on a direct-current (“DC”) voltage in the low frequency driving mode. 
     
     
       9. The display apparatus of  claim 8 , wherein the first gate signal and the emission signal are generated based on the first gate high voltage level and the first gate low voltage level in the writing frame of the low frequency driving mode and in the holding frame of the low frequency driving mode. 
     
     
       10. The display apparatus of  claim 1 , wherein the first gate signal has a first frequency in the low frequency driving mode,
 wherein the second gate signal has a second frequency in the low frequency driving mode, and 
 wherein the emission signal has a third frequency that is greater than the first frequency and the second frequency in the low frequency driving mode. 
 
     
     
       11. The display apparatus of  claim 10 , wherein the second gate signal is generated based on a first gate high voltage level and a first gate low voltage level in the writing frame of the low frequency driving mode, and
 wherein the second gate signal is generated based on a second gate high voltage level that is lower than the first gate high voltage level and a second gate low voltage level that is greater than the first gate low voltage level in the holding frame of the low frequency driving mode. 
 
     
     
       12. The display apparatus of  claim 11 , wherein the first gate signal is generated based on the first gate high voltage level and the first gate low voltage level in the writing frame of the low frequency driving mode, and
 wherein the first gate signal is generated based on the second gate high voltage level and the second gate low voltage level in at least one of a plurality of holding frames of the low frequency driving mode. 
 
     
     
       13. The display apparatus of  claim 12 , wherein the emission signal is generated based on a direct-current (“DC”) voltage in the low frequency driving mode. 
     
     
       14. The display apparatus of  claim 13 , wherein the emission signal is generated based on the first gate high voltage level and the first gate low voltage level in the writing frame of the low frequency driving mode and the holding frame of the low frequency driving mode. 
     
     
       15. The display apparatus of  claim 10 , wherein the first frequency of the first gate signal is greater than the second frequency of the second gate signal in the low frequency driving mode. 
     
     
       16. The display apparatus of  claim 1 , further comprising:
 a level shifter configured to generate a first gate clock signal, a second gate clock signal, and a third gate clock signal based on a first native gate signal, a second native gate signal, a third native gate signal, and the gate power voltages, and further configured to respectively output the first gate clock signal, the second gate clock signal, and the third gate clock signal to the first gate driver, the second gate driver, and the third gate driver; 
 a first high voltage generator configured to generate a first gate high voltage level; 
 a second high voltage generator configured to generate a second gate high voltage level; 
 a first low voltage generator configured to generate a first gate low voltage level; 
 a second low voltage generator configured to generate a second gate low voltage level; 
 a first switch configured to selectively output one of the first gate high voltage level and the second gate high voltage level to the level shifter; and 
 a second switch configured to selectively output one of the first gate low voltage level and the second gate low voltage level to the level shifter. 
 
     
     
       17. The display apparatus of  claim 16 , wherein the display apparatus further comprises a driving controller that includes the level shifter, the first high voltage generator, the second high voltage generator, the first low voltage generator, the second low voltage generator, the first switch, and the second switch. 
     
     
       18. The display apparatus of  claim 16 , wherein the display apparatus further comprises a driving controller and a power voltage generator,
 wherein the driving controller comprises the level shifter, and 
 wherein the power voltage generator comprises the first high voltage generator, the second high voltage generator, the first low voltage generator, the second low voltage generator, the first switch, and the second switch. 
 
     
     
       19. A display apparatus comprising:
 a display panel comprising a pixel including a first switching element of a first type and a second switching element of a second type that is different from the first type; 
 a first gate driver configured to output a first gate signal to the first switching element of the first type; 
 a second gate driver configured to output a second gate signal to the second switching element of the second type; 
 a third gate driver configured to output an emission signal to the pixel; and 
 a data driver configured to output a data voltage to the pixel, 
 wherein the display apparatus is operable in a low frequency driving mode, and the low frequency driving mode includes a writing frame and a holding frame, 
 wherein at least one of gate power voltages used to generate the first gate signal, the second gate signal, and the emission signal has a first voltage level in the writing frame in the low frequency driving mode and a second voltage level that is different from the first voltage level in the holding frame of the low frequency driving mode, 
 wherein the data voltage is applied to the pixel in the writing frame of the low frequency driving mode, 
 wherein the data voltage applied to the pixel in the writing frame of the low frequency driving mode is maintained in the holding frame of the low frequency driving mode, 
 wherein the first gate signal and the second gate signal have a first frequency in the low frequency driving mode, and 
 wherein the emission signal has a second frequency that is greater than the first frequency in the low frequency driving mode. 
 
     
     
       20. The display apparatus of  claim 19 , wherein the first gate signal and the second gate signal are generated based on a first gate high voltage level and a first gate low voltage level in the writing frame of the low frequency driving mode, and
 wherein the first gate signal and the second gate signal are generated based on a second gate high voltage level that is lower than the first gate high voltage level and a second gate low voltage level that is greater than the first gate low voltage level in the holding frame of the low frequency driving mode. 
 
     
     
       21. The display apparatus of  claim 20 , wherein the emission signal is generated based on a direct-current (“DC”) voltage in the low frequency driving mode. 
     
     
       22. The display apparatus of  claim 21 , wherein the emission signal is generated based on the first gate high voltage level and the first gate low voltage level in the writing frame of the low frequency driving mode and in the holding frame of the low frequency driving mode. 
     
     
       23. A method of driving a display panel, the method comprising:
 outputting a first gate signal to a first switching element of a pixel of the display panel, wherein the first switching element is of a first type; 
 outputting a second gate signal to a second switching element of the pixel of the display panel, wherein the second switching element is of a second type that is different from the first type; 
 outputting an emission signal to the pixel; and 
 outputting a data voltage to the pixel, 
 wherein the display panel is operable in a low frequency driving mode, and the low frequency driving mode includes a writing frame and a holding frame, 
 wherein at least one of gate power voltages used to generate the first gate signal, the second gate signal, and the emission signal has a first voltage level in the writing frame of the low frequency driving mode and a second voltage level in the holding frame of the low frequency driving mode, both of the first voltage level and the second voltage level corresponding to a same gate state selected from a gate-high state and a gate-off state, 
 wherein the data voltage is applied to the pixel in the writing frame of the low frequency driving mode, and 
 wherein the data voltage applied to the pixel in the writing frame of the low frequency driving mode is maintained in the pixel in the holding frame of the low frequency driving mode.